Fix cache error, where users see incorrect graphs
Fix cache error, where users see incorrect graphs

The cache lookup did not take into account the instance uuid, when fetching
the instance's datapoints. The cache would return the latest datapoints for a
similar request made to any instance. Now the cache key includes the uuid.

CCI-MOC/GUI-Backend,CCI-MOC/GUI-Backend,CCI-MOC/GUI-Backend,CCI-MOC/GUI-Backend